LMFP Electrode Coating with Pickled Collector for Low Porosity
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Solution Overview
Problem
Lithium manganese iron phosphate (LMFP)-based positive electrodes for lithium-ion cells face challenges in achieving low porosity, high basis weight, and maintaining flexibility, which are essential for high energy density and industrial-scale manufacturing.
Innovation Solution
A current collector made of a metal strip, coated with a composition of lithium manganese iron phosphate and lithium oxide, undergoes chemical pickling to reduce porosity and increase basis weight while retaining flexibility, with specific formulations and coatings that enhance the electrode's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If an electrode comprises LMFP active material with high specific surface, then the electrode has high porosity (40% or more), but this makes it difficult to produce electrodes for high energy density electrochemical cells
Solution Approach 1:
The invention changes the particle size parameter of the LMFP active material to a controlled range (D10≥5μm, D50≥10μm, D90≥15μm) to reduce specific surface area. This parameter change directly addresses the contradiction by lowering porosity from 40% or more to below 40%, enabling high energy density electrode production while maintaining adequate active material content
2Quantity of substance
If the basis weight of the electrode is increased to obtain high energy density, then the electrode has higher energy capacity, but the flexibility of the electrode decreases
Solution Approach 1:
The invention changes the particle size distribution parameters of the LMFP active material (controlling D10, D50, D90 values) to optimize the electrode structure. This allows achieving high basis weight (2-10 mg/cm²) while maintaining flexibility by creating a more uniform particle packing that preserves mechanical properties despite increased material loading
3Stability of the object's composition
If the porosity of the electrode is reduced to increase energy density, then the electrode has lower porosity, but the flexibility of the electrode decreases
Solution Approach 1:
The invention changes the particle size parameters of the active material to reduce porosity while simultaneously optimizing the particle size distribution to maintain electrode flexibility. The controlled D10≥5μm, D50≥10μm, D90≥15μm specifications create a particle structure that packs efficiently (reducing porosity below 40%) while maintaining mechanical compliance for industrial manufacturing
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The approach results in electrodes with reduced porosity, higher basis weight, and improved flexibility, leading to enhanced chargeability and reduced polarization, with the electrode maintaining its mechanical integrity and flexibility during manufacturing and operation.
Implementation Method 1
A current collector made of a metal strip, coated with a composition of lithium manganese iron phosphate and lithium oxide, undergoes chemical pickling to reduce porosity and increase basis weight while retaining flexibility
Data Source
AI summary
The present invention relates to an electrode comprising a current collector formed by a metal strip which is coated on at least one of the faces thereof with a composition of electrochemically active materials, the composition comprising at least one lithium manganese iron phosphate having the following formula: LixMn1-y-zFeyMzPO4, where M is selected from the group consisting of B, Mg, Al, Si, Ca, Ti, V, Cr, Co, Ni, Cu, Zn, Y, Zr, Nb and Mo, alone or in a mixture, with 0.8≤x≤1.2; 0.5≤1-y-z<1; 0.05≤y≤0.5 and 0≤z≤0.2; the current collector having undergone chemical pickling of at least one of the faces thereof.